I have been looking at this adverb "PRWI", and trying to determine what kind
of adverb it is.
It also has some funny accentuation to go with it. This is found also in UBS
as well as Nestle-Aland 27th ed. Greek Text.

Is there a name to this accentuation? Is this the way it is found in the
MSS? Is there a case connected to this adverb? (As in Dative)?